This disclosure relates to medical devices and more particularly to an implantable lead.
The medical device industry produces a wide variety of electronic and mechanical devices for treating patient medical conditions such as pacemakers, defibrillators, neuro-stimulators and therapeutic substance delivery pumps. Medical devices can be configured to be surgically implanted or connected externally to the patient receiving treatment. Clinicians use medical devices alone or in combination with therapeutic substance therapies and surgery to treat patient medical conditions. For some medical conditions, medical devices provide the best and sometimes the only therapy to restore an individual to a more healthful condition and a fuller life. One type of medical device is an implantable neurological stimulation system that can be used to treat conditions such as pain, movement disorders, pelvic floor disorders, gastroparesis, and a wide variety of other medical conditions. The neurostimulation system typically includes a neurostimulator, a stimulation lead, and an extension such as shown in Medtronic, Inc. brochure “Implantable Neurostimulation System” (1998). More specifically, the neurostimulator system can be an Itrel II® Model 7424 or an Itrel 3® Model 7425 available from Medtronic, Inc. in Minneapolis, Minn. that can be used to treat conditions such as pain, movement disorders and pelvic floor disorders. The neurostimulator is typically connected to a stimulation lead that has one or more electrodes to deliver electrical stimulation to a specific location in the patient's body.
Clinicians often use a stylet to stiffen and steer the lead during implantation. The stylet is typically inserted in the lead proximal end through a stylet guide. Previous stylet guides are typically manufacted from a material that is harder than the lead body. When stylets are inserted or withdrawn from a hard stylet guide, the stylet can become bent or scratched potentially causing damage to the stylet lumen or the lead body. Additionally, previous hard stylet guides typically use a separate component to be added to the lead proximal end complicating manufacturing and creating a risk that the seal between the stylet guide and the lead proximal end could leak. An example of an optional stylet guide is shown in U.S. Pat. No. 6,216,045 “Implantable Lead And Method Of Manufacture” by Black et al. (Apr. 10, 2001). For the foregoing reasons, there is a need for an implantable lead with flared stylet lumen that reduces the potential for damage to a stylet and seals the lead proximal end.